Signaling system for railways.



.J. M. WALDRON. v SIGNALING SYSTEM FOR RAILWAYS.

APPLICATION FILED SEPT. 30. 1908.

A SHEETS-SHEET 1.

Patented May 18, 1909.

Emit we 5 011a J. M. WALDRON. SIGNALING SYSTEM FOR RAILWAYS. APPLICATIONPILED'SIZPT. a0, 1908.

Patented May 18, 1909.

2 SHEETS-SHEET 2.

until the latter has cleared the block which tance.

' at a moderate speed, which mightbe safely equipment.

nnirnn STATES Parent OFFICE.

JAMES M. WALDRUN. OI YO.\'I(EIlt ,i\l-l\\' YORK, ASSIHNOB. 'll) 'llllfiUNION SWITCH d: SIGNAL COMPANY, OF SWISSVAIJE, PENNSYLVANIA. ACORPORATION OF PENNSYLVANIA.

SIGNALING SYSTEM FOR. RAILWAYS.

Specification of Letters Patent.

Patented May 18, 1909.

Application filed September 30, 1908. Serial No. 455,523.

To all whom it may concern:

Be it known that l, J AMES M. WAiionox, a citizen of the United States,residing at Yonkers, in the county of \Vestchester and State of NovYork, have invented certain new and'useful Improvements in SignalingSystems for Railways, of which the following is a specification.

In the block signaling of railways, the greatest degree of-protection isobtained by the use of such systems wherein the territory affecting thecontrol of any block signal is extended beyond the location of the nextsucceeding block signal, a determined dis- Oftentimes, and especiallywhere the distance between signals is the minimum in which atrain can bestopped fronrfull speed, the entire distance between the next twosucceeding signals is used for the overlap. This method of control isold in the art, but it advantageous when automatic train stops are usedin connection with the block signals. The reason is, that full bakingdistance may thus be obtained beyond each signal wherein a train can bestopped by the automatic stop in the event of the trains overrunning asignal and its stop in the danger position. The use of train stops thusarranged in signaling systems of the class described is awell knownfeature in modern railway signaling where high speed and great frequencyof trains prevail. The method, however, does not provide for trains aproaching one another at slow speeds to t us obtain the. greatest numberof-train movements in a minimum amount of. time. At stations, inparticular, where regular stops are niade, a train is by the method ofsignaling hereinbelfore described held quite. adistance in the rear ofone at the station,

includes the station stop, thus preventing the approach to the stationof the rear train done if not for the restriction imposed by the It isan object of the present invention to enable one train to thus close inupon another provided it has first so reduced its speed to make itsapproach a matter of reasonable safety. To accomplish this I haveapplied to one of the signals a time device which when the block signalis at'safety holds a circuit open controlling another signal. When thetrain passesv the signal at safety l regular stops or tions foradvancing train:

lapse of a predetermined interval, one sut i-' cient to enable a trainon passing the signal to'move at a. very much restricted speed up -tothe next signal, whereupon the next signal will move to safety by virtueof the circuit being closed through the time device, to permit the train(at this very much reduced speed) to enter the next block andirrespective of the normal means provided in the block sy stem forpreventing its movement to safety while a train occupies a part of theterritory it governs. By means of this invention, therefore, nurterialtime is to be saved in reducing the headway of trains passing throughstations or other points where stops or. restricted speeds are regularlyscheduled, or, if desired, my improvement may be applied continuou ly toeach signal of the system and thus ei'Lc'. a saving in l'readway at anypoint along the linewhere 7 slow down are not scheduled, but Wherecmergenci from time to time may cause them to occuin Theautomatic'closing in of one train to within one block of another in theevent of trouble to the first train is also thus rendered possible andassistance thus may he more quickly obtained than under the regularblock equip ment. 7

I do not lay claim herein to the use of automatic stops in connectionwith the systems shown nor to'any novelty in their control or operationas these are old in the art as arranged, as are various other methods oftheir arrangement. and control in conjunction with block systems. WhileI have shown them in the drawings and described them briclly' I regardthem as purely auxiliary devices to the signals themselves and usedsimpl to enforce the proper oliiser ance of the sig als by trainmen. Itherefore do not limit myself to the use of automatic stops in carryingout my-invention, but recognize that they may or may not be used asfinancial or other conditions justify and entirely at the dis cretionand Within the skill of modern signal engineers. I also show in mydrawings and specifications the ordii'iary forms and arrangements ofblock signals and apply my invention in such a manner thereto t it theregular signal is employed under all condilled in the art that It isobvious to those ill) a secondary or Q calling-on signal may be used foradvancing the trains when the overlapping sections are eliminated byaction of in the rear of a station in an overlapping sigis deemedunnecessary.

nal system, a train being shown as standing at the station and holdingat danger two signals S and S in its rear as is customary in suchsystems. Fig. 2 is the same as Fig. 1 except the addition therein of awell-understood arrangement of automatic train stops controlled by andoperating in conjunction with the signals in a manner also wellunderstood. Fig. 3 shows in vertical cross section a form of time devicewhich may be employed for retarding the closure of a circuit after asignal moves from safety until a predetermined time has elapsed. Fig. 4shows the application of the device shown in Fig. 3 to a well known formof automatic railway signal.

Similar letters and numerals of reference designate corresponding partsin all of the figures.

Referring now to Fig. 1, the block signals are designated by the lettersS, S, S and S". i

l have shown three com lete block sections, A, B and C, each of whic isprovided with a track circuit. Each track clrcuit as shown, comprises atransformere, c and c or any other well known means of supplyingalternating current or if desired a direct current generator such as adynamo or primary or secondary batteries may be used, and a relay ortranslating device a, b and c, which is designed to operate from thegenerator of its particular track circuit.

As track circuits are so well understood in the art of signaling and asmy invention does not embrace any novelty in their equi ment orarrangement further description 0 them The manner of forming the blocksections is also immaterial to my invention and any desired means may beemployed for that purpose. As shown, the block sections are formed byinserting insulation or otherwise dividing one of the track rails. Thetype of railway signal is immaterial, though I prefer to use anautomatic type of railway signal. I have shown in Fig. 3 what iscommonly known as an electro-pneumatic railway signal, the signal device.9 being moved from its danger to its safety position by means of asuitable mechanism here shown as comprising a piston movable in acylinder .9 under the infi l-cow of compressed air which is'supplied "oma main pipe s under the control of an electrically operated valve '8This is all well understood in the art.

The signal S is held at safety normally.

may be traced as follows: battery 2, wire 3,

contact of relay to, wire 5, contact of relay 1), wire 6, signalmechanism, and wire 1 to battery 2. Thus, relays a and I) both normallycontrol this signal.

Signal S is controlled by a circuit which may be traced as follows:,battery 2, wire 3, contact of relay 1), wire 7, contact of relay 0, wire8, signal mechanism, and wire 1 to battery 2. Thus, relays b and 0 bothcontrol this signal.

It is assumed in Fig. 1 that all trains will be brought to a stop at thestation hence the control of signal S by an overlapping section beyondsignalS is omitted as is customary in practice under such conditions.Should some trains not stop at the station it would be expedient tocontrol the signal S by a track circuit beyond signal S also, but such acontrol would not alter the application of my invention to the situationfrom the diagrams of it shown in Figs. 1 and 2.

Assume a train to be standing at the sta tion as shown. The relay (1will then be deenergized and the circuits described as controlling thesignals S and S will be inter rupted at the relay contacts. The signal Sand S will in'consequence be retained at danger as shown. A followingtrain upon entering section C will shunt current from the relay 0which'will then drop its armature and open the circuit on signal S atthat point, thus putting the signal to danger. Under ordinary methodsand without my improvement the train could not proceed beyond the signalS so long as that signal remained partly under the control of tracksection A while a train occupies Wholly or in part the rails of thatsection as shown.

It is evident that if the following train could proceed past signal S ata very much reduced speed, or it it were compelled. in

other words, to run from signal S to "S at such a slow speed as tocompel its entrance to section B at a speed of say five miles an hour,and if the section B were made reasonably short the chance of the trainsobtaining such speed on arriving at signal S and overrunning that signaland into collision with thetrain at the station would be very remote,while the use of automatic stops at each signal effective when thelatter are at system that when signal S he signal S is in the dangerwould be most ellective in allowing such closing in of trains reasonablyif not wholly sale. The time interval between trains that may by use olmy improvement he obtained is of material advantage upon railroadsemploying frequent service and o )erating at times up to the full limitof tieir capacity. Additional capacity for trains is thereforeobtainable with the use of my improvement without reducing to anymaterial extent the safety to be obtained by the block system to whichit is attached.

To this end I apply my invention to signal S which comprises a timedevice, a form of which is shown in Figs. 3 and 4, operating a circuitcontroller, and so embody it in the set to danger by a train passing it,the piston in the cylinder of the time device slowly descends and alterthe lapse of a predetermined time ell cts the closure of contactscomprised in a circuit for the signal 'lhe contacts are here shown aswith wires 9 and 3, and located at signal. S Vs hen these contacts areclosed a circuit is established from battery.2, wire 3, wire 9 throughthe contacts a" and i of the time device to contact of relay 7), wire 6,signal mechanism wire 1 to hattery 2. Theetl'ect of this closed circuitis to operate to safety the signal S to permit the advancing train toenter under its reduced speed into block B, providing that train has soredura d its speed as to consume the same time in passing through blockC as the time device consumed in closing its contact alter the signal Swhich released it,

moved to danger under the influence of the train on passing it.

in Fig. 2 l have shown my invention in connection with train stops, thetrain stopping devices being designated P P The train stop control showninvolves a normal stop position of the stop mechani ism and each devicehas two or nuts, one to clear it and the other to hold it clear underthe proper conditions. circuit controllers in the circuits shown areoperated by the signals and train stops only, "he tract; relay contactsnot directly at train stop circuits, asunig. he done if dcsired, themethod shown being one in common use. I

desired construction pr e 5K8 and 8 respectively, l closing wire 3 towire 14 when the l g al S is in the clear position; F closing -l psition; l wire 8 to wire when an the clear position.

the signal S .ing the 3 position. The train stops P P and P are of thewell known form requiring the presence of an electric current to move tothe down or non-engaging position, the absence of such current allowinggravity to raise the train stop arm to the train engaging ositio1i. Theclearing circuit for train stop P starts from battery), wire 3, signalcircuit controller F, wire 14, mechanism P, wire 1 back to battery 2,and requires signal S to he in the clear position before the train stopcan he cleared.

A train in passing signal S setting it to the stop position, operatescircuit controller F and closes the following circuit: battery 2, wire3, contact F wire 13, contact K (closed when train stop was cleared bythe clearing circuit), wire 14, mechanism P wire 1, hack to battery 2.This latter circuit is for the purposeof holding the train stop clearunder the train when the signal S in being passed was set to the stopposition and circuit controller F operated to open the clearing circuit.Similarly, the clearing circuit for train stop P takes battery 2, wire3, circuit controller l on signal 8, wire 12, train stop mechanism Pwire 1. hack to battery 2.

When a train passes signal S circuit controller F on signal S is closedand the fol lowing circuit is established, battery wire 3, circuitcontroller F wire 11, circuit con troller K on train stop P", wire 12,train stop rnechanisn'i 1, wire 1, hack to hatter-y 2. The clearingcircuit for train stop I starts from battery 2, wire 3, circuitcontroller F wire 15, mechanism P", wire 1 hack to battery 2.The-holding circuit will come from the signal in rear, not shown, viacontroller K wire 15, to mechanism P, to wire I, to hatteryaz. It willhe understood that when the train passes the signal "the time devicewill close a circuit on si nal S in the manner hereinhefore descrited tohave it operate the circuit controller F in Fig. 3 is shmvn a timedevice which may,

Qe emplhyed and which comprises a cylinder A that is fitted with apiston B and hollow rod (1. On the under side of the piston is mounted acheck valve D held seated against the piston by spring E which issecured in a' compressed state by the nuts and washer F on the downwardextension of the piston. Through the piston are a number of holesdr'lled vertically through the surface up a hich the valve seats. If thepiston lrc drawn up and the cylinder be partly lilled the check valveinstantly seats ircuit controllers K Y and IQ of any desired constr arep widcd on the train stops P t and close the co the train stops are withliquid the atmospheric pressure acting upon the liquid will force thelatter to open the valve and fill the space under the piston that wouldotherwise constitute a vacuum 1 and retard the upward movement of thepiston. Upon descent of the piston again 'ents 1 ports he of the liquidhack throng through which it descended under the piston. There isanother passage, however, provided for this return of the liquid to thechamber above the piston through the hollow piston rod the hole in whichextends down through the piston head and its lower extension intocommunication with the chamber under the piston. On descent of thepiston'the liquid is forced up through this passage past a pin valveformed on the lower end of stem G mounted in the hollow piston in theman'- ner shown, so that the freedom With-which the liquid passes thispin valve and through the perforations S S- S into the chamber abovethe,piston may be capable of regula- I tween them a metal ring i ofslightly larger diameter mounted by suitable insulating material tostand electrically separated from all other parts of the piston and itsattachments. Mounted on the cylinder head is an insulatin block carryingtwo contact springs 'i (0 y one of which is shown) which are secured toit but fully insulated from the balance of the structure. This metalring i and the contact springs constitute a circuit controller forcontrolling a circuit on an advance signal. When the signal is at dangerand the piston is in its lower position as shown this metal ringlies incontact with the two sprin s, electrically uniting them. As the signalwith the piston upward and contact with the spring is severed. When thesignal moves to danger the piston does not return to its lower positionat once hut slowly descends after the signal has assumed-danger underthe restrictions imposed upon the flow of the liquid through the pistonrod until the ring rests in contact with the two springs. In this waythe closure of the special circuit upon the signal in advance of the onecarrying the time device is closed at whatever interval is desired afterthe signal with the time devicchas assumed danger.

Fig. 4 shows the cylinder supported by some fixed part of the signalstructure while a lug extends from the rod by which the ger position bythe tram, said time signal is operated to a point under the disk I bymeans of which the piston is elevated with the signal rod. During .thereverse movement-of the signai red the lug on the moves to safety thering is carried clear position.

disks allowing them and the piston to descend at will.

Having thus described my invention, what I claim is: i V

1. In a signaling system for railways, plurality of signals, trackcircuits lying between the signals, means actuated by the track circuitsfor controlling the movements of the signals, and means actuated by thesignals for eliminating a portion of the track circuit control of thesignals after the lapse of a predetermined time following the setting ofthe signals to danger by trains.

2. In an automatic block system for railways the combination of thesignals and means adapted to extend the control of the signals by one ormore track circuits in advance of that one forming the block section,and means actuated by trains for eliminating one or more of the saidadvance track circuits from theocontrol of the. signal to the end thattrains moving at restricted speeds may follow one another at closerintervals underv wise.

3. In an automatic block system for railways wherever the control ofeach signalis in part affected by trains in the'next succeeding block,means actuated by trains onpassing one signal for clearing the nextsignal in advance'independently of the means that may there be retainingthe si al in advance at danger, after a given time as elapsed followingimmediately u on the setting of the first signal to danger y the train.

4. In a railway signaling system, the combination of a plurality ofblock sections, railway signals for each .of said block sections, traincontrolled means comprising track c1rcuits for holding at danger in therear of.a

bloc-k section occupied by a train one or more of the railway signals ina position to indicate danger, a time device provided at a railwaysignal in the rear of the last railway signal held in the danger ositionby the train, and a circuit controlled by said time device for causingthe next railway signal in advance which is in its danger pos tion tomove to its 5. In a railway s'gnaling system, the combination of aplurality of block sections, rail- .way signals for each of said blocksections,

train controlled means comprising track circlear signals than would bepossible othercuits for holding at danger in the rear of a block sectionoccupied by a train one or more of the railway'signalsin a position toindicatedanger, a time device operating a circuit controller and rovidedat a railway signal in the rear of the ast railway signal held in itsdandevice acting to clear the circuit controller when the railway signaloperating it is in its danger position, and a circuit controlled by saidrod simply recedes from contact with the 1 time device for causing thenext railway sigto move to its clear position.

nal in advance which is in its-danger position I l of the last railwaysignal held in the danger 6. In a railway signalling system, the com- 1osition by the train, and a circuit controlled binntion of a pluralityof block ections, raill y said time device for causing the next milwuysignals for each of said block sections, i way signal in advance whichis in its danger trztin controlled means comprising track cir- 5position to move to its clear position. suits for holding at danger inthe rear ofa i In testimony whereof I have signed my block sectionoccupied by a train one or more name to this specification in thepresence of (if the railway signals in a posiltlion to indicate 1 twosubscribing witnesses.

ztn 'er, a trainsto in mec anism at each y r railway signal and ntiolled by said railway JAMES WALDRON signal to be in its engaging ornon-engaging position according to whether the railway signal indicatesdanger or safety, a. time de- Witnesses:

H. W. GRIFFiN, H. O. HAMILTON.

. vice provided at a railway signal in the rear

